Multiple-switchboard apparatus



2 Sheets-Sheet. 1.

-llazenteaSeptIl 5, 1893.

A A w. M. GooDRIDGE.

, MULTIPLE SWITGHBOARD APPARATUS.

www! l\ x l A A MIE .A (MH y 1 4 MH.; I o k N N ('N-O Model.)

sheets-sheet 2. W. M. GOODRIDGE. v -MULTIPLE SWITGHBOARD APPARATUS.

(Nlo Model.)

Patented Sep't.r5, 1.*89'3.

UNITED STATES PATENT OFFICE.

WILLIAM M. GOODRIDGE, OF HIGHLAND PARK, ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS.

M ULTlPLE-SWITCHBOARD APPARATUS.

SPECIFICATION forming part of Letters Patent No. 504,345, dated September 5, 1893.

l Application led J'anuary12,1889 Serial No. 296.192. '(No medal.)

' To all whom it may concern.-

v following is a full, clear, concise, and exact de Y Be it known that I, WILLIAM M. GOOD- RIDGE, a citizen of the United States, residing at Highland Park, in the county ofLake and State of Illinois, have invented a certain new and useful Improvement in Multiple-Switchboard Apparatus, (Case No. 8,) of which the scription, reference being had to the accompanying drawings, forming a part of this speci'- fication. v r v The object of my invention is to provide ready means for making the connections and disconnections between the telephoney lines at the central oiiice.k I

As to the state of the art prior to my invention reference is made to Letters Patent No. 283,334, granted Leroy B. Firman August 14, 1883, and No. 305,021, granted Charles to connect any two lines together upon any one of the switch boards whichthe operator may choose to elect or happen to find convenient; All the connections between sub-` scribers lines must be made at the board upon which one of the `two lines to be connected has its terminal cord and; plug. By the use of double cords, as hereinafter described, the

operator is enabled to make the ordinary connection upon the board on which is placed the calling subscribers annunciator so that the calling annunciator may be utilized `as a clearing out signal,-and also the same lines when desired may be connected together be.

tween their switches upon any one of the other boards as may be convenient, say at night or on Sundays whenthe calls are few.

My invention consists in placing the individual annunciators of the different lines each v between the regularA spring jack of the line Y on thelastboard and fthe lanswering spring jack of the line upon'one of theaboards, in

v ranged as hereinafter described;` I

combinationwith ypairs of cordsfand plugs and switching apparatus-constructed and ar- Myinvention also relates to the manner of attaching the cord to the terminal plug and to the listening'in key.

My invention will be readily understood by reference to the accompanying drawings, in whichl Figure 1 is a diagram showing two telephone lines connected with two multiple switch boards, together with the key board apparatus embodying my invention. Fig. 2

themanner of connecting the cord therewith. Fig. 3-is a perspective View of the listening in key. Fig. 4 is a View of the same from below.

I will describe my invention first as illustrated in Fig. 1. Telephone line a, is conswitchY b upon the first board and thence through the spring and contact of switch c on dividual annunciator d on the iirst board and thence through the answering spring jack f of the irst board, and thence to ground. Line gin the same way is connected through spring jack ,'of the second board and thence through individual yannunciator 7c on the second board and thence through answering spring jack Z 'and thence to ground. It will be understood that a large number of such lines are provided in each exchange, each line being proyvided with a differentspring jack switch on each of the switch. boards, and each line including an individual annunciator and an answering spring jack upon one of the boards. The lines are thus distributed between the operators at the different boards so that each operator will answer the calls of a particular set or group of subscribers. Each telephone line is provided with its test circuit as described in said Scribner patent. Thus line a, is provided with the test circuit Z which is connected with the frame or test piece of each of the switches b c f. Telephone line g in like manner is provided with its test circuit Z2 connected in a similar manner with the insulated frame or test .piece of each of the switches h cf Z of line g. At each board I provide pairs of flexible cords and plugs. In Fig. l I have shown one such pair at eachof the switch boards. At board l the terminal plugs m n shows detailed sectional views of the plug and the second board, and thence through the inswitch h of the first board, spring jack switchY nected through the spring and contact of are shown in their normal positions resting in their sockets in the cord shelf. Ilugm is the terminal of cord m in the circuit of which is included the usual calling key m2; the other cord 'n' of the pair is connected with terminal plug n and in the circuit ot' this cord n is ineluded the usual calling key n2. The operators telephone o is included in a ground branch which may be connected or disconnected at will from the cords by means of a listening in key o as shown. A test battery o2 is included in circuit with the telephone.

I will now describe the operation of my system as illustrated in Fig. l. Suppose a call is Sent in over line g throwing down the annunciator la; the operator at board 2, listening at telephone p, will immediately insert one of the pairs of plugs into the answering spring jack Zot the line. Thus as shown plug p of the pair which is nearest the spring jack Z is inserted in said answering spring jack Z. When plug p is thus inserted, the listening in key p2 will be in position to connect the telephone 19 to the pair of cords, so that the operator listening at telephone p may receive the order sent over line g. Assume this order to be for connection with line a, the operator by means of the other plug p3 of the pair first touches the test piece of spring jack switch c to determine whether line a is busy. If the line is busy the circuit of test battery p4 will be closed through telephone p to the tip of plug p3 and thence over test wire Z to the switch at which connection is made with said line a, and the cross being established between line a and test circuit Z the circuit of test battery p4 will be complete to ground through telephone p and the operator listening at telephone p will hear the click due to the closing of the circuit and will know that the line is busy. If, however, the line tested is idle the operator will insert plug p3 as shown into spring jack switch c, thus completing the circuit. By means of calling key p5 she then sends current over line a to call up the subscriber wanted. Thereupon listening in key p2 is brought to the position shown, disconnecting the telephone p from the circuit of the connected lines. The two lines thus connected will include in their circuit the individual annunciator lo of the calling subscriber; the shutter of annunciator lo having been restored, the annunciator thus left in circuit serves as a clearing out device. The operator may then proceed with other connections in the same manner. It' now, after these lines have been connected, shutter k should fall the operator will know that it is a disconnecting signal since she will nd the answering spring jack corresponding to shutter la occupied. I preferably place the spring jack switches upon the upright portion q of the board in the usual manner. The plugs I preferably arrange upon a cord shelf q. The annunciators I place upon the frame q2 in rows in front of the operators, while the calling keys and listening in keys are placed upon the shelf qs below. By this arrangement the plugs and cords are separated from the keys and are not liable to become tangled, the annunciators occupying a position intermediate between the cord shelf and the key shelf.

As shown in Fig. 2 the flexible insulated cord r is inserted through an opening in the end of the plug handle. The end of this cord being bared is inserted at an angle through another opening r. The rubber sleeve 'r2 is then placed over the metallic portion of the plug as shown so as to bind the cord in position and is the only part of the plug that is composed of insulating material, the bite or friction of the bare cord passing the open,

ing fr', serving to prevent the cord from being pulled out, while at the same time a most perfect electrical connection is provided between the iiexible metallic cord and the metallic portion of the plug.

As shown in Figs. 3 and 4 the plate s may be considered as connected with the line leading to the cords while the plate s is connected with the line or wire leading through the telephone and test battery to ground. When the metallic lever s2 is between pieces s and s the telephone will be connected with the cords, the lever s2 forming the medium of connection between said springs or contact pieces s s. The spring or contact s3 I preferably place in the position shown; this contact or spring s3 as used in my system has no electrical connection with any of the lines; it serves simply as a guide for the lever s2.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl. The combination with two telephone lines each connected with a separate spring jack switch on each of two or more switch boards, of an answering spring jack and an individual annunciator upon one of the boards in each of said lines, the individual annunciator being placed between the switch of its line on the last board and the answering spring jack switch thereof and upon the same board with the said answering spring jack vswitch and double cord switching apparatus,

whereby said two lines may be connected together, the individual annunciator of the calling line being left in circuit as a clearing out signal device.

2. A telephone line in combination with spring jack switches, one in each of two or more switch boards, an annunciator included in the line at one of the switch boards and an answering spring jack switch upon the same board with the annunciator included in said line between said annunciator and the ground.

3. The combination withtwo telephone lines each connected with two or more switch boards and each including an `answering spring jack switch in its circuit between the individual annunciator thereof and the ground, of a pair of cords with terminal IOO IIO

plugs, one plug ofthe pair inserted in the answering spring jack of one of the lines and the other plug inserted in the switch of the other line upon the same switch board, whereby the individual annunciator of the line having the plug inserted in its answering spring jack is left in circuit as a clearing out device, while the individual annunciator of the other line is disconnected from the circuit.

4. The combination with a pair of cords provided with terminal plugs, of a ground branch including a telephone, a test battery and a single listening-in key, telephone lines each connected with two or more switch boards, and each provided with a test circuit, whereby while either of said plugs is inserted in the spring jack switch of one line'the other plug of the pair may be used to test any other line at the same switch board; substantially as and for the purpose specified.

5. A plug with a flexible insulated cord inserted through an opening in the end of the plug handle and extended through another opening lr at an angle to the first opening, the insulating covering being removed from the end of the cord passing through said opening fr', in combination with the rubber sleeve r2 placed over the metallic portion of the handle of the plug, whereby the cord is held in place and provided with a perfect electrical connection with a metallic portion of the plug, substantially as and for the purpose specified.

In witness whereof I hereunto subscribe my name this 2d day of January, A. D. 1889.

WILLIAM M. GOODRIDGE.

Witnesses:

GEORGE P. BARTON, ELLA EDLER. 

